Optimize hopper restart during spawner batch loading

[Copilot]

During server startup, SpawnerData.updateStackSize() calls restartHopperForSpawner() for every spawner being loaded. With hundreds/thousands of spawners, this creates an O(n) bottleneck that causes severe delays or hangs.

Changes

• SpawnerData: Added optional restartHopper parameter to setStackSize() to defer hopper restart during batch operations

  public void setStackSize(int stackSize, boolean restartHopper) {
      // ... existing logic ...
      if (restartHopper && plugin.getHopperHandler() != null) {
          plugin.getHopperHandler().restartHopperForSpawner(this.spawnerLocation);
      }
  }

• SpawnerFileHandler: Pass restartHopper=false in loadAllSpawnersRaw() to skip per-spawner hopper restarts during batch load

• WorldEventHandler: Call restartAllHoppers() once after all spawners are loaded, replacing O(n) individual restarts with single batch operation

In-game stack size changes continue to trigger immediate hopper restart as expected.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• jitpack.io
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED -XX:MaxMetaspaceSize=384m -XX:+HeapDumpOnOutOfMemoryError -Xms256m -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/gradle-launcher-8.8.jar -javaagent:/home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/agents/gradle-instrumentation-agent-8.8.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 8.8 (dns block)
• maven.enginehub.org
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED -XX:MaxMetaspaceSize=384m -XX:+HeapDumpOnOutOfMemoryError -Xms256m -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/gradle-launcher-8.8.jar -javaagent:/home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/agents/gradle-instrumentation-agent-8.8.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 8.8 (dns block)
• mvn.lumine.io
• nexus.iridiumdevelopment.net
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED -XX:MaxMetaspaceSize=384m -XX:+HeapDumpOnOutOfMemoryError -Xms256m -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/gradle-launcher-8.8.jar -javaagent:/home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/agents/gradle-instrumentation-agent-8.8.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 8.8 (dns block)
• repo.bg-software.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED -XX:MaxMetaspaceSize=384m -XX:+HeapDumpOnOutOfMemoryError -Xms256m -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/gradle-launcher-8.8.jar -javaagent:/home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/agents/gradle-instrumentation-agent-8.8.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 8.8 (dns block)
• repo.codemc.io
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED -XX:MaxMetaspaceSize=384m -XX:+HeapDumpOnOutOfMemoryError -Xms256m -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/gradle-launcher-8.8.jar -javaagent:/home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/agents/gradle-instrumentation-agent-8.8.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 8.8 (dns block)
• repo.glaremasters.me
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED -XX:MaxMetaspaceSize=384m -XX:+HeapDumpOnOutOfMemoryError -Xms256m -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/gradle-launcher-8.8.jar -javaagent:/home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/agents/gradle-instrumentation-agent-8.8.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 8.8 (dns block)
• repo.nightexpressdev.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED -XX:MaxMetaspaceSize=384m -XX:+HeapDumpOnOutOfMemoryError -Xms256m -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/gradle-launcher-8.8.jar -javaagent:/home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/agents/gradle-instrumentation-agent-8.8.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 8.8 (dns block)
• repo.opencollab.dev
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED -XX:MaxMetaspaceSize=384m -XX:+HeapDumpOnOutOfMemoryError -Xms256m -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/gradle-launcher-8.8.jar -javaagent:/home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/agents/gradle-instrumentation-agent-8.8.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 8.8 (dns block)
• repo.papermc.io
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED -XX:MaxMetaspaceSize=384m -XX:+HeapDumpOnOutOfMemoryError -Xms256m -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/gradle-launcher-8.8.jar -javaagent:/home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/agents/gradle-instrumentation-agent-8.8.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 8.8 (dns block)
• repository.minecodes.pl
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --add-opens=java.base/java.util=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.lang.invoke=ALL-UNNAMED --add-opens=java.prefs/java.util.prefs=ALL-UNNAMED --add-opens=java.base/java.nio.charset=ALL-UNNAMED --add-opens=java.base/java.net=ALL-UNNAMED --add-opens=java.base/java.util.concurrent.atomic=ALL-UNNAMED -XX:MaxMetaspaceSize=384m -XX:+HeapDumpOnOutOfMemoryError -Xms256m -Xmx512m -Dfile.encoding=UTF-8 -Duser.country -Duser.language=en -Duser.variant -cp /home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/gradle-launcher-8.8.jar -javaagent:/home/REDACTED/.gradle/wrapper/dists/gradle-8.8-bin/dl7vupf4psengwqhwktix4v1/gradle-8.8/lib/agents/gradle-instrumentation-agent-8.8.jar org.gradle.launcher.daemon.bootstrap.GradleDaemon 8.8 (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

When loading spawners using SpawnerFileHandler.loadSpawnerFromConfig(), it calls setStackSize(), which internally triggers SpawnerData.updateStackSize().

Everything loads fine when there are only a few spawners.
However, when loading a large number of spawners and the hopper feature is enabled, the process becomes extremely slow or gets stuck.

The bottleneck seems to come from this line:

if (plugin.getHopperHandler() != null) {
plugin.getHopperHandler().restartHopperForSpawner(this.spawnerLocation);
}

It appears that restartHopperForSpawner() is being called for every single spawner during loading, which is very inefficient.

Is there a way to optimize or refactor this

if you remove the code then when ingame when stacksize change the hopper stop working

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.